Influence of Concrete Material Property on Failure Mode of Steel–Concrete Connection Under Monotonic Load

This study aimed to investigate the structural behavior of the steel–concrete connection under monotonic loading, utilizing different types of concrete. Both experiment and finite element analysis under the same conditions were performed. First, three specimens with embedded steel anchors were cast using three different concrete materials, which were ordinary Portland cement concrete, geopolymer concrete, and prepacked concrete. The pull-out test was performed to observe the failure modes of each specimen occurring in the form of cracking, crushing, and other forms of concrete failure. The load–displacement relationship of the structures was measured so that the ultimate capacity could be determined. Second, finite element analysis using finite element code, COM3D employed the same experimental conditions and was carried out to observe the nonlinear behavior of structural concrete and verify the pull-out test results. In both the experiment and analysis, the highest ultimate tensile capacity was obtained from ordinary Portland cement concrete, followed by prepacked concrete. The geopolymer concrete showed the lowest ultimate capacity. Load–displacement relationship obtained from the experiment and analysis showed a similar trend. The difference in stiffness attributed to the interface between steel and each concrete type could be observed. In the experiment, the ordinary Portland cement concrete and prepacked concrete exhibited shear failure behavior; however, geopolymer concrete showed splitting tensile failure. On the other hand, the analysis results showed splitting tensile failure in all cases.